Taking into account the nature of this work, we need a sample of
non-active galaxies for our analysis. To eliminate AGN hosts, we
cross-matched our sample of 8000 galaxies with the MPA-JHU SDSS DR7
emission-line catalogue of \(\sim \)  920000 sources, using a
cross-matching radius of 2 arcsec. We obtained a total of 7940
counterparts with available redshifts and emission lines with
signal-to-noise ratio S/N \(>\)  3. For these galaxies, we plotted the
[1]} BPT-NII diagram as shown in Fig. REF , using
the emission-line ratios of \([NII]\lambda 6584/H\alpha \)  and
\([OIII]\lambda 5007/H\beta \) . To separate star-forming (non-AGN)
galaxies from composite and AGN galaxies we used the separation limits
given by [2]} and [3]}. We also
checked the number of Seyfert 2 and LINER sources using the separation
limit of [4]}. We found in total 2744 (35%)
star-forming galaxies, 1918 (24%) composites, 594 (7%) Seyfert
2s, and 2684 (34%) LINERs.
